Brake



M y 1936. w. THOMPSON 2,041,980 7 BRAKE I Filed April 15, 1935 Patente dMay 26, 1 936 3 Claims.

This invention relates to the class of'brakesv Application April 13,1935, Serial No. 16,232

and pertains particularly to mechanicalbrakes of the type normallyemployed on motor vehicles. The primary object of the present invention5 is to provide a new and novel type of internal expanding brake whereinscrew means is employed for imparting motion to the brake bands toeffect their contact with an adjacent drum. Another objectof theinvention is to provide a brake having a screw and nut'operating meanswhichis of simple design but by which rapid actuation of the brakesmaybe effected with a minimum of motion of the footor hand operatingmechanism.

The invention will be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawing forming part of this specification; with the understanding,however, that the invention is not confined to any strict conformitywith the showing of the drawing but may be changed or modified so longas such changes or modifications mark. no material departure from thefeatures of the invention.

In the drawing:

salient Figure 1' illustrates'a sectional view of a brake mechanismtakenon the line l-l of Figure 2 perpendicular-to the axis of the brakeshowing the present improved mechanism coupled there'- Figure 2 is asectional view taken horizontally through the operating mechanism, a.portion of In carrying out the present invention there is illustrated afriction means which comprises two ating' mechanism about to bedescribed, might be connected. v Y Disposed between the free ends of theband or 55 the two shoes illustrated, is the actuating mechbrake shoes,each of which is indicated by .the.

anism comprising the present invention and this includes an elongatedhousing 6 of polygonal cross section which has an end extended through asuitable opening in the plate 3 and is secured to this plate by the ears1 so as to lie parallel with the axle 2, which forms the axis of. thebrake. 5 At the outer end ofthe housing 6, a head plate 8 is secured towhich is swivelly coupled the oscillatable shaft 9 which has its majorportion within the housing 6.

.the housing 6 is provided with the coarse thread l0 and a nut H issecured tothe shaft by means This portion of theshaft 9 in of thesethreads, which nut is of the same cross section as the housing 6 so thatwhen the shaft 9 is oscillated, the threadswill force the nut to movelongitudinally in the housing. k

At its outer end the thread carrying shaft 9 has a lever arm l3 securedthereto by means of which motion may be imparted-to the shaft from themotor vehicle foot or hand lever through suitable connecting mechanism,which is not shown.

, -Within the'drum of the brake, the housing 6 has the two cars l4attached thereto and to each of these ears is pivotally attached a bellcrank lever which is indicated generally by the number 15 and which hasthe two arms l6 and H. The housing 6 has an opening I8 thereinthrougheach sidewall and adjacent the ear l4, and a bell crank is shifted atthe point of joinder between its 'two arms upon an ear M with the longerarm [1. thereof extending through the adjacent housing opening I8 intothe interior of the housing 6 while the shorter arm lies within the drumand adjacent to the outside of the housing side wall.

1 Within the drum each bell crank has the free end of its long arm I!pivotally attached to one end of a link l9 which has its other endpivotally attached to an ear 20 carried upon the forward faceof the nutl-l.

Adjacent each of its free ends, the brake band drum, the free'end of theshort arm 16 of each bell crank is pivotally connected with the adjacenthinge ear 22 by a short link 23.

"Fromthe foregoing, it will be apparent that in the operation of thepresent brake mechanism, when a pull is applied to the lever l3 tooscillate theshaft 9 in'one direction, the nut Ii will be movedoutwardly on the shaft toward the end 8 of the-housing so as to pull thelinks 19 and oscillate the bell cranks i5 in the necessary direction tospread the free ends of the brake band apart and force them to contactwith the drum. By reversely actuating the lever E3, the nut will bemoved forwardly and will pull the ends of the band away from the drum soas to release the brake.

Having thus described the invention, what is claimed is:

1. In a brake including a drum and friction means mounted in the drumincluding two ends separable for effecting contact of the means with thedrum, actuating means comprising an elongated guide body disposedbetween the said ends to extend parallel with the axis of the drum, athreaded nut member carried by said guide means for movement thereon, ascrew supported for oscillatory motion in said guide means and havingsaid nut threaded thereon, means for efiecting the oscillation ofsaid-screw, a bell crank pivotally mounted adjacent each of the saidends and having a pair of divergent arms, one of the arms of each bellcrank extending into the guide means, connecting means between said nutand the free end of each of the bell crank arms extending into the guidemeans and pivotal connecting means between the free end of the other armof each bell crank and the adjacent one of said ends.

2. In a brake including a drum and friction means mounted thereinincluding two ends sepa-' rable for effecting contact of the means withthe drum, a. screw mounted for oscillation adjacent said ends with itslongitudinal axis extending transversely of the drum, a nut threaded onthe screw, means retaining the nut against rotation with the screw butpermitting its movement longitudinally thereof, and means pivotallycoupling the nut with the said friction element ends whereby the endswill be made to positively move relav tive to the drum by the shiftingof said nut in either direction on the screw.

3. In a brake including a drum, friction means mounted in the drumincluding two ends separable for effecting contact of the meanstherewith and a fixed plate closing one side of the drum and having anopening therethrough, an elongated closed housing having an end extendedthrough said opening and into proximity with said ends, a screwextending longitudinallyin the housing and oscillatably mounted in theend thereof remote from the drum, the housing being of polygonalcross-section, a nut in and conform ing in contour with thecross-sectional outline of the housing and threaded on the screw, meansat the outer end of the screw for eiiecting its oscillation, andmechanism coupling the nut through the wall of the housing with the endsof the irlction means, whereby relative movement of said ends will beefiected upon movement of the nut.

WILLIAM THOMPSONE

